In Malawi, planting trees in fields of maize bumps up yields

During my recent trip to Malawi, I saw that the expansion of agriculture, of illegal logging, and of charcoal production are decimating the country’s once-forested hillsides, causing soil to wash into rivers, wetlands, and lakes. This loss of topsoil is reducing crop yields, putting stress on agriculture-dependent communities, and leading to increasingly intense land use.

The degradation gets even more severe with natural disasters and the impact of climate change. As a result, Malawi is losing about 1.7 percent of its GDP to floods and drought.

Malawi’s Shire River Basin is home to 3 million people and supports the livelihoods of about 5.5 million. The largest river in the country, the Shire, flows some 270 miles (400 kilometers) from Lake Malawi to the Zambezi River in Mozambique. Along the way, it feeds wetlands, irrigates fields, supports fisheries and wildlife, and provides water for households and hydropower.

However, the Shire River Basin is deeply emblematic of the environmental challenges Malawi as a country is facing. Unsustainable practices in the watershed area have resulted in erosion, siltation, and nutrient loss, all made worse by competition among water users. How can this vicious cycle be broken?

One answer is commitment to change at high-levels of government. Malawi’s Minister of Natural Resources, Energy and Mining has expressed his deep concerns about natural resource degradation in his country, and is intent on strengthening efforts to restore deteriorated landscapes. His commitment is backed up by Malawi’s nationally determined contribution under the Paris Climate Agreement, as well as the country’s participation in the African Forest Landscape Restoration Initiative, a pan-African effort to restore 100 million hectares of degraded land.

Trees shelter crops

Trees on farms are beneficial to building the resilience of both ecosystems and livelihoods. They help control soil erosion, replenish nutrients, and restock soil organic matter, all while providing diversified sources of income to communities. Trees represent a valuable carbon sink, and are key to providing the ecosystem services communities depend on.

Known as Tree-Based Systems (TBS), reintroducing this technique into farming could be the solution to regenerating degraded landscapes in Malawi and other African countries.

Part of this may come directly from Malawi’s own farmers. A recent PROFOR/World Bank/TerrAfrica study on Taking to Scale Tree-Based Systems in Malawi identified that 20 percent of the country’s arable land, farmers are already using Tree-Based Systems as a way to provide households with fuelwood, timber, and an additional source of income.

If implemented properly, the systems can be immensely helpful to increasing agricultural productivity. For instance, a 1995 study found that maize planted under Faidherbia trees, had increased yields between 4 percent and 53 percent. Faidherbia, an acacia that sheds its leaves in the rainy season, is used for nitrogen-fixing and erosion control.

Scaling-up tree planting should be easy

What is especially promising about TBS is its potential to be carried out at scale. Promoting the practice of intercropping trees in maize fields in the Shire River Basin and beyond could save the Malawian government around $71 million annually in fertilizer subsidies. It could also help remove the equivalent of 1.6 metric tons of carbon dioxide per hectare every year. In short, this relatively simple practice could help Malawi significantly boost its food and energy security, and contribute towards its pledge to act against climate change.

Malawi is not the only country where TBS has the potential for widespread use. It has been well used, for example, in Rwanda, where human population densities are even higher and most of the land is intensively cultivated, much of it on moderate to steep slopes. With what natural forest remains confined to protected areas, fuel, and timber supplies largely rely on Eucalyptus trees, commonly planted around farms and in woodlots on the steepest, least fertile land.

A study of pathways for scaling up TBS in Rwanda suggests that a key strategy would be to promote agroforestry systems that improve the productivity of existing crop systems. Institutions must also make the effort to mainstream agroforestry training in national agricultural extension and support systems.

While Malawi, Rwanda, and other countries face an uphill battle in reconciling immense environmental pressures with development, TBS and other agroforestry efforts offer a great opportunity to turn a vicious cycle into a virtuous one.

Comments

These messages are important. To add, I just wanted to draw attention to a recent paper in the Forest Policy and Economics Journal (http://www.sciencedirect.com/science/article/pii/S1389934116304592) which documents the extent of on farm tree growing across a number of African countries, using the LSMS-ISA data .

Malawi is one of the countries covered. The data are open access and the exercise may be useful by way of baseline in examining future endeavours (for an early WP version see http://documents.worldbank.org/curated/en/819461471962574880/pdf/WPS7802.pdf).